Device for detection of transmission from remote control

ABSTRACT

An apparatus is provided which gives feedback to a user of a remote control device, such as that for a television, to indicate when excessive use of the remote control (channel surfing) is occurring. The device detects transmission from a remote control device and counts the transmissions during an predetermined time period. When a predetermined maximum number of commands from the remote control device is received, an indication of such is provided to the viewer. This indication may take the form of a visual indication such as flashing a message, an auditory alarm, disabling of the remote control device by jamming the inferred signal, or automatically controlling operation of the remote control device, which may include turning off the device. Programming of the apparatus through use of the remote control to accomplish advanced features is also provided.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a device to provide an indication to auser of a remote control device that the user is engaging in "channelsurfing".

2. Description of the Related Art

A television viewer can today receive a great number of channels on hisTV. It is not unusual that the number of channels is 20 or more. Whenthe choice is so varied, the TV viewer often switches between thechannels with his remote control in his desire to find other channelswith better TV programs.

Switching between channels brings the viewer to another channel believedto be better than the previous one. But after a short while he discoversthat the new channel does not offer any better programs and starts toswitch channels again. When the switching is repeated several times itis called "channel surfing". The viewer finally ends up surfing insteadof actually watching TV.

SUMMARY OF THE INVENTION

The object of the invention is to make the viewer stop or reducesurfing.

The inventive device, that has a detector built in, is placed close tothe TV set, according to FIG. 1. The detector detects each time theviewer activates his remote control.

When the inventive device (1) has detected a certain number ofactivations for the remote control (3), during a defined length of time,the inventive device provides an indication that surfing is going on.

The indication can vary depending on how the viewer chooses to beinformed that he is surfing. The indication is given by the inventivedevice (1) for a certain length of time, perhaps a couple of seconds, inthe form of:

an acoustic sound,

a flashing lamp

a voice message which is replayed,

a short passage of music which is played,

lights up a sign with a suitable text e.g. "STOP", "GIVE UP", "GO TOBED".

the inventive device sends a power-off signal to the TV set.

a jammer transmitter, that locks out the function of the remote control(3), is switched on and makes it impossible to continue surfing during acertain time length.

Depending on which way of signalling the inventive device uses, theinventive device can assume different shapes and forms according to FIG.2.

When the remote control uses infrared light, the jammer transmitter inthe inventive device uses the method to blend or send false signals tothe TV set remote control receiver. Since the TV set receives falsesignals the TV set can not take in signals from the ordinary remotecontrol.

The function of the jammer transmitter is constructed so that theinventive device first gives a warning before the jammer transmitter isactivated. Through the warning the viewer is notified that he hasapproximately 10 seconds to decide which channel he wants to view duringthe time period that the jammer transmitter is activated. The timelength of the period can be relatively long, e.g., 10 to 30 minutes.

Instead of having a certain length of time during which the jammertransmitter is activated, it can be more suitable to have random timelength when the jammer transmitter is activated. The time length israndomized each time surfing is detected and can be set from seconds toseveral minutes. This way, the viewer shall not know in advance when thejammer transmitter will be activated. The viewer shall not be able todetermine when it will be possible to start surfing again.

For some viewers, the optical or acoustic indications are not enough tomake him stop surfing. In these cases the inventive device is equippedwith a reset button which has to be activated to stop the indication.The reset button is designed so that the viewer has to rise from hischair to push it. How long the reset button has to be held down dependson the intended degree of difficulty for the viewer to reset theinventive device. Instead of the above described messages and actions itcan sometimes be better to show how frequent the viewer uses the remotecontrol, e.g., a frequency counter.

The frequency counter can be realized as a number of lamps in a bar thatare illuminated depending on the frequency of use, or as a numeric valueon a display.

Of course, the inventive device can be used for all sorts of equipmentthat are controlled by a remote control, e.g. radio receivers, CDplayers or videos, to prevent frequent changes of channels and programs.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates one embodiment of the invention placed by a TV set.

FIG. 2 illustrates different exterior appearances of the invention.

FIG. 3 is a simplified block schematic illustrating one embodiment ofthe invention.

FIG. 4 is a simplified block schematic illustrating one embodiment ofthe invention where the invention is equipped with a jammer transmitter.

FIG. 5 is an electrical circuit schematic where the invention isrealized in a microprocessor.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates the inventive device (1) placed on a TV set (2). Theremote control (3) sends a command (pulse train) (4) which is receivedby the TV set (2) and also received by the inventive device (1).

In FIG. 3 the inventive device is explained in greater detail in theblock schematic, herein showed for a remote control (3) that usesinfrared light as transmission media. When the remote control (3) isactivated the photo diode (5) is activated by a pulse train of IR-light(4). The pulse train from the photo diode (5) is transmitted to thedetector (6), which consists of an amplifier (7), a bandpass filter (8),and a limiter (9). The amplified and bandpass filtered pulse train isproduced as a signal (10) that is transmitted to a surf detector (11).

The function of the surf detector (11) is achieved when the signal (10)passes through the diode (12) and the resistive element (13) and chargesthe capacitor (14). When the remote control is used the voltage acrossthe capacitor (14) will rise, as measured at (16). When the voltage at(16) has risen to a certain level, surfing is detected via signal (24).

The frequency of use of the remote control (3) that is to be consideredas surfing is decided by the values of resistors (13), (15) and (23).The resistor (23) value is changed by the control device (29).

To prevent the surf detector (11) from responding to normal use of theremote control (3), the two resistance elements (13) and (15) havesuitable values according to the following: The resistor (13) determinesthe threshold of how many commands from the remote control (3) arereceived during a period of time, while the length of the period of timeis controlled by the resistor (15).

Most remote controls (3) on the market repeat a chosen command until thebutton on the control is released. This means that the inventive devicewill receive a great number of pulses on the signal (10). The pulseswill rapidly cause the voltage (16) to rise and surfing will beindicated. Such false indications become especially prevalent when oneuses a video recorder.

When a video recorder is used it is usual that the viewer uses the fastforward command button on the remote control (3) and holds it down for aperiod of time, e.g., to fast forward through commercial advertising. Asa result, the remote control (3) during the entire fast forward sequencewill send pulses which are received and translated into signal (10).

To prevent this type of false indication of surfing the followingactions can be taken: A viewer can not change channels faster than 3 to4 times per second. This means that the pulse trains can be transmittedat the fastest every 250 ms. If they come with higher frequency, it canbe assumed that it is the remote control (3) that generates them, asopposed to actual surfing.

By measuring the time between the pulse trains is it possible todetermine whether they come from a repeating remote control (3) or ifthey are the beginning of a surfing sequence.

An activity detector (17) provides a control signal (18) when the signal(10) changes level with a frequency higher than once every 250 ms.

When this happens the switch (19) is opened by the control signal (18)and the inventive device (11) is switched off.

Through this arrangement the inventive device will not indicate surfingfrom the use of fast forward on the video recorder or if any button onthe remote control (3) is activated during a longer period of time.

The activity detector (17) is constructed in the same way that the surfdetector (11) but with a different time constant according to the abovedescribed assumption.

The voltage (16) from the surf detector (11) is fed via signal (20) to acomparator (21) that compares the voltage of (20) with a referencevoltage (22) that is pre-set by the resistor (23). If the voltage (20)is greater than the reference voltage (22), a signal (24) is set active,and surfing is detected. The signal (24) activates a multivibrator (25).The output (26) of the multivibrator (25) is, in FIG. 3, connected to alamp and a speaker (27). The lamp makes the sign (28) flash. The pulsingof the speaker (27) and the lamp is achieved as the pulse frequency onthe multivibrator (25) is set on a couple of Hz.

To make the signal (24) last for a short while after the surfing hasstopped, the comparator (21) incorporates a hysteresis function.

In FIG. 4 the inventive device is shown in a form modified from that ofFIG. 3. Identical reference numbers are used, and are not explainedagain. In FIG. 4 the inventive device has been completed with a jammertransmitter than consists of a timer (37), a multivibrator (39), anIR-light diode (40), a pseudorandom generator (41) and a reset device(42).

In this embodiment a digitized network is used to realize the surfdetector (11) that consists of a counter (33) and a timer (32). Theactivity detector (17) is replaced with a monostable multivibrator (30).

Just as described in FIG. 3 with respect to false surf indications,these must be eliminated in this embodiment also.

A retriggerable monostable multivibrator (30) is triggered by the pulsetrain on the signal (10). The monostable multivibrator (30) provides apulse on the signal (31) only if the pulse train on signal (10) comesmore seldom than once every 250 ms. If the pulse trains occur withhigher frequency they will retrigger the monostable multivibrator (30)and the pulse on the signal (31) will not be generated. In that case thepulse will not occur until the last pulse train is transmitted, e.g.,when the time between the pulse train is longer than 250 ms. Themonostable multivibrator (30) is set on 250 ms, according to theassumption described in FIG. 3.

Assume that the timer (32) is in its original state and that the counter(33) is reset. When a pulse is transmitted to the timer (32) through thesignal (31), the timer (32) will start and run for approximately 10minutes, even if more pulses reach the signal (31) during this timeperiod. The timer (32) is not retriggerable. The timer (32) releases thecounter (33) with the signal (34). The counter (33) begins to count thenumber of pulses on the signal (31). When the period measured by thetimer (32) has elapsed, the counter (33) is reset by the signal (34). Atthe next pulse on the signal (31), the timer (32) will be started againand the procedure will be repeated.

If the counter (33), while the timer (32) is running, is able to count,e.g., 25 or more pulses, the signal (35) is given, indicating thatsurfing is detected. The signal (35) starts the timer (36) which givesthe signal (24) that activates the multivibrator (25). The function ofthe timer (36) is to make surf indication active during a short timeafter surfing has been detected. The signal (35) also forces the timer(32) to its original state which then gives the signal (34) that resetsthe counter (33). The timer (32) is now ready to restart on the nextpulse on signal (31).

When surfing shall be indicated can be regulated by the control device(29), which decides when the counter (33) shall give the signal (35),that is how many pulses that shall be counted by the counter (33) onsignal (31) before signal (35) is given. The timer (32) determines howlong the counter (33) shall count, a suitable time for the timer (32)being 10 minutes. If the inventive device is equipped with the jammertransmitter, it is activated when the signal (24) disappears. In thisway the viewer is notified with speaker (27) and the sign (28) that thejammer transmitter soon will be switched on. When the signal (24)disappears the timer (37) is started and its output (38) activates themultivibrator (39). The multivibrator (39) pulses the IR-diode (40) witha frequency of around 40 kHz, which disturbs the remote control receiverof the TV set when the light of IR-diode light on the TV set remotecontrol receiver detects these false signal. Suitable time for the timer(37) is between 10 and 30 minutes.

The multivibrator (39) will be powered until the signal (38) is removed.The signal can disappear in three ways:

1. Signal (39) from the pseudorandom generator (41).

2. The time in the timer (37) has elapsed.

3. The reset device (42) is activated.

The occasions 1 and 3 is described below.

At the same time that the signal (24) is activated, a pseudorandomgenerator (41) is activated, its function being to give the signal (39),after a random length of time, that lasts from seconds to tens ofminutes. When the signal (39) is given the timer (37) will be reset andthe signal (38) disappears which turns off the multivibrator (39). Bythis arrangement the jammer transmitter will be powered for a randomlength of time.

The viewer can, if he wishes, turn off the jammer transmitter throughthe reset device (42), which in turn resets the timer (37).

In FIG. 5 the inventive device is constructed with the aid of a microcomputer (50), PIC 16c54 from Microchip Technology Inc. USA. In thisexample, an IR-receiver (51) and an amplifier are incorporated into thesame integrated circuit (51), IS1U60 from the Japanese company Sharp.Commands from the remote control (3) that are sent with IR-light (4) areamplified in the amplifier and the limiter (52), bandpass filtered infilter (53) that has a middle frequency of approximately 38 kHz, andthereafter the signal is demodulated in the demodulator (54). On thedemodulator output gate (10) a binary pulse train is provided which isfed into the micro computer through the input gate RBO. The electricalconnectors (55) are used for settings in the same way as the devices(29) and (42). The resistors (56) are pullups used to guarantee alogical "one-level" when the contacts (55) are open. The RC-net (57) isthe time contact to the clock generator for the micro computer (50). Thelight diode (59) lights up the sign (28). The outputs RBO . . . RB3control each function (28), (40), (27) and (58). The inventive device ispowered by battery (60).

The software in the micro computer (50) is mainly an application of thefunction of the inventive device as described in FIG. 4. When a microcomputer is used to implement the inventive device, complex functionsare easily added to the inventive device, which otherwise wouldn't bepossible in an analog implementation as shown in FIG. 3, or wouldrequire too much space in a digitized network as shown in FIG. 4.

Examples of complex functions are:

Detecting and recognizing one or several commands from the remotecontrol (3).

Transmission of commands from the inventive device (1) to the TV set(2).

Identification of the viewer, by making the viewer send a special codefrom the remote control (3).

Receiving of control commands to the inventive device (1) from theremote control (3).

Detecting commands is useful in cases when the viewer also looks atTeletext. Through training of the inventive device, from the remotecontrol (3), it can be made to recognize commands that mean the vieweris viewing Teletext and switch off the surf detector. Otherwise theviewers repeated actuation of the buttons on the remote control would beinterpreted as channel changes when they actually are page number forthe Teletext.

Instead of that, the viewer instructs the inventive device which buttonis used for changing to Teletext, or this can be programmed into theinventive device already at the factory. This can also be applied forcommands that controls the video recorder. These commands shall not bedetected as surfing. It is also detected when the viewer changes backfrom Teletext to TV, and the surf detector is switched on again. Thiscommand is programmed into the inventive device to be able to detectsuch a command.

The IR-diode (40) can, of course, also be used to transmit commands tothe TV set. Such a command can be to switch off the TV set (2) whensurfing is detected, or to send a certain sequence of commands, e.g.,choose a special TV channel when surfing is performed or to send aspecific sequence at a specific time.

Training of these commands, or other commands that shall be transmittedto the memory of the inventive device, for recognition or commands thatshall be transmitted, is made by activating the remote control, pointingit at the inventive device and pushing a certain button (55), thetraining is completed. The fact that training is going on and iscompleted is shown by the light diode (58).

Identification of the viewer or receiving of the control commands fromthe remote control (3) can be done by transmitting a specific sequence(code) from the remote control (3) e.g. "decrease brightness", "1", "2","3", "4", which will be detected by the inventive device. Identificationcan be used to shut down the inventive device for a while. Another codecan be used to change the presets in the inventive device, whichotherwise have to be done with the devices (29) and (42). A third codemay be used to inform the viewer how many channel changes he has done,or other such statistics. When the inventive device detects such a codeit will collect the number of channel changes performed so far from thebuilt in memory. This is possible by using a counter in the microcomputer that counts each time a change of channel is made, and when thecode "information about the number of channel changes" is detected, theinventive device will transmit the number on the light diode (40) as thenumber commands from the remote control (3).

By sending the number as number commands the commands will be detectedby the TV set. To make it easier to interpret the number of changes ofchannels, the inventive device first will send the command "change toTeletext" and after that send the number of channel changes. The numberof changes will correspond to a Teletext page with that number, e.g.page 135 means that 135 changes of channels have been made.

I claim:
 1. A device for detection and indication of frequent use of aremote control device for an apparatus, comprising:a detector whichdetects when the remote control device is used by detecting infraredlight transmissions from the remote control device; a counter whichcounts a number of detections during a predetermined time period; and aremote jamming device, capable of preventing use of the remote controldevice; wherein when the number of detections exceeds a predeterminednumber during the predetermined time period, an indication is provided.2. The device of claim 1, wherein the remote jamming device comprises:aninfrared light transmitting diode to jam the transmissions of the remotecontrol device; a timer for controlling a length of a period duringwhich the remote jamming device is active; a pseudorandom timinggenerator which, when activated, enables the remote jamming device foran indeterminate period of time; and a multivibrator designed to pulsethe infrared light transmitting diode at a frequency which will jam thetransmissions of the remote control device.
 3. The device of claim 1,wherein the remote jamming device is designed to prevent use of theremote control device for a set period of time.
 4. The device of claim1, wherein the remote jamming device is designed to prevent use of theremote control device for an indeterminate period of time.
 5. The deviceof claim 1, wherein the remote jamming device is controlled by amicrocomputer.
 6. The device of claim 1, wherein the remote jammingdevice further comprises a reset mechanism, the reset mechanismdisabling the remote jamming device when the reset mechanism isactivated.
 7. A device for detection and indication of frequent use of aremote control device for an apparatus, comprising:a detector whichdetects when the remote control device is used by detecting infraredlight transmissions from the remote control device; and a counter whichcounts a number of detections during a predetermined time period;wherein the device is programmable to identify extraneous commands fromthe remote control device, said extraneous commands not being counted assaid detections; and wherein when the number of detections exceeds apredetermined number during the predetermined time period, an indicationis provided.
 8. A device for detection and indication of frequent use ofa remote control device for an apparatus, comprising:a detector whichdetects when the remote control device is used by detecting infraredlight transmissions from the remote control device; and a counter whichcounts a number of detections during a predetermined time period;wherein the device is programmable to recognize at least oneidentification code provided through the remote control device, andwherein the recognition of the at least one identification code altersoperation of the device; and wherein when the number of detectionsexceeds a predetermined number during the predetermined time period, anindication is provided.
 9. A device for detection and indication offrequent use of a remote control device for an apparatus, comprising:adetector which detects when the remote control device is used, thedetector comprising a photo diode sensitive to infrared light and aconditioning circuit which conditions an output of the photo diode; anda counter which counts a number of detections during a predeterminedtime period; wherein the conditioning circuit comprises:an amplifierconnected to an output of the photo diode; a bandpass filter connectedto an output of the amplifier; and a limiter connected to an output ofthe bandpass filter; and wherein when the number of detections exceeds apredetermined number during the predetermined time period, an indicationis provided.
 10. The device of claim 9, wherein the conditioning circuitfurther comprises a resistor-capacitor network designed to only passchanges in an output signal of the detector representing successive usesof the remote control device which are separated by more than a minimumtime period.
 11. The device of claim 10, wherein the counter comprises:aresistor-capacitor network; and a comparator.
 12. The device of claim 9,wherein the conditioning circuit further comprises a monostablemultivibrator designed to produce conditioned pulses which representchanges in an output signal of the detector representing successive usesof the remote control device which are separated by more than a minimumtime period.
 13. The device of claim 12, wherein the counter comprises:aconditioned pulse counter connected to an output of the monostablemultivibrator; and an elapsed duration timer providing a time periodduring which the conditioned pulses are counted by the conditioned pulsecounter.
 14. The device of claim 13, wherein the counter furthercomprises a reset mechanism to reset a count of the conditioned pulsesdetected during a current said time period during which the conditionedpulses are counted by the conditioned pulse counter.
 15. The device ofclaim 13, wherein the counter further comprises an indication timer usedto determine how long the indication is provided.
 16. The device ofclaim 9, wherein the counter is implemented with a programmedmicrocomputer.